Electrocochleography for Hearing Loss

(AB-ECOG Trial)

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: Medical College of Wisconsin

Disqualifiers: Chronic otitis media, malformed cochlea, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 3

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how the inner ear reacts to sound during and after cochlear implant surgery. It tests whether monitoring these reactions using electrocochleography (ECochG) can improve the implant’s performance. Participants are divided into two groups: one where the surgeon uses sound response feedback and one without it. Ideal participants have significant hearing loss and qualify for cochlear implants, without any ear conditions such as chronic infections or previous ear surgeries. As an unphased trial, this study offers participants the chance to contribute to innovative research that could enhance cochlear implant outcomes.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that electrocochleography is safe for cochlear implant surgery?

In a previous study, researchers found that electrocochleography (ECochG), a test used during cochlear implant surgery, is generally safe for patients. ECochG measures electrical signals in the inner ear, aiding surgeons in placing the implant correctly and minimizing ear damage during surgery.

Research has shown that using ECochG can lower the risk of harm to the inner ear, leading to better hearing outcomes. No major reports of problems directly caused by ECochG have emerged, indicating that patients tolerate it well during cochlear implant surgery.

Overall, ECochG provides surgeons with real-time information, enhancing the safety and effectiveness of the implant procedure. While all medical procedures carry some risk, ECochG appears to have a strong safety record based on current studies. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about using electrocochleography (ECochG) during cochlear implant (CI) surgery because it adds a new layer of real-time monitoring that could help prevent trauma to the inner ear. Unlike the standard CI surgery, where surgeons rely solely on their skills and experience, ECochG provides immediate feedback on the auditory nerve's responses during electrode insertion. This technique allows surgeons to adjust their approach if they detect a drop in signal amplitude, potentially reducing the risk of damage and improving patient outcomes. By integrating this audible feedback, the method aims to make the surgery safer and more precise, which could lead to better hearing restoration for patients.

What evidence suggests that Electrocochleography is effective for hearing loss?

Research has shown that electrocochleography (ECochG) can help protect hearing during cochlear implant surgery. In this trial, participants will be divided into two groups: one group will have the audible ECochG response on, allowing surgeons to monitor ECochG signals in real-time and adjust their approach to prevent further hearing loss. The other group will undergo surgery without ECochG monitoring, following the current standard of care. Studies have found that monitoring ECochG signals can alert surgeons to possible ear damage. Specifically, patients who experienced drops in ECochG signals during surgery tended to have worse hearing preservation a year later, highlighting the method's importance in surgical decisions. Overall, ECochG is becoming a valuable tool for preserving hearing after cochlear implants. ^{5 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for individuals aged one year and older who meet the standard requirements for cochlear implant surgery, have a specific level of hearing loss, and no ear abnormalities that would interfere with the implant. It's not suitable for those with auditory neuropathy, chronic ear infections, malformed cochlea, ear tubes in place or past middle ear surgeries.

Inclusion Criteria

You can hear sounds at certain frequencies with a volume of 80 decibels or less.

No additional handicap that would prevent study procedures from being followed

I am at least one year old.

Exclusion Criteria

I have long-term ear infections.

I have a malformed cochlea.

You have ear tubes in your ears.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-30 days

1 visit (in-person)

Surgery

Cochlear implant surgery with ECochG monitoring during electrode insertion

1 day

1 visit (in-person)

Initial CI Activation

Initial activation of the cochlear implant and audio assessment

3-5 weeks post-surgery

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

12 months

Multiple visits (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Electrocochleography

Trial Overview

The study is examining how well the inner ear responds to sounds during and after cochlear implant surgery using a technique called Electrocochleography. This could help understand the effectiveness of cochlear implants post-operation.

How Is the Trial Designed?

Group I: Arm 2: Audible ECochG Response On Experimental Treatment 1 Intervention

This condition will have the audible ECochG response on and available to the surgeon. In this condition, the surgeon perform a conventional electrode insertion while listening to the running ECochG signal for drop in amplitude (suggesting impending trauma). If no drop is detected, insertion will proceed to the full electrode length according to the standard-of-care. If an ECochG amplitude drop is observed, the surgeon will place this observation in its clinical context and evaluate insertion parameters, (i.e., insertion vector, insertion speed, etc.), customary practice with conventional CI surgery, but here supplemented by the ECochG response. In the case of an ECochG amplitude drop that does not recover, the standard-of-care practice of achieving a full electrode insertion will be followed.

Group II: Arm 1: Audible ECochG Response Off Experimental Treatment 1 Intervention

Arm 1: Audible ECochG Response Off This condition is identical to the current standard-of-care for conventional CI surgery used worldwide. The surgeon will perform his or her electrode insertion without ECochG monitoring. Minute manipulations of the electrode are a normal part of conventional electrode insertion; manipulations such as redirecting the insertion vector or slowing down insertion speed will be made, as deemed necessary by the surgeon. A full electrode insertion will be performed, as appropriate. The ECochG responses will be recorded, but the surgeon will be blinded to this information during surgery.

Who Is Running the Clinical Trial?

Medical College of Wisconsin

Lead Sponsor

Trials

645

Recruited

1,180,000+

Published Research Related to This Trial

In a study of 55 patients undergoing cochlear implantation, an amplitude drop of 61% in real-time electrocochleography (ECochG) during electrode insertion was identified as a significant predictor of a 25% loss in hearing one month post-surgery.

The findings suggest that clearly defined ECochG events, particularly those with a steep slope of 0.2 µV/sec, can help guide surgeons to preserve acoustic hearing during cochlear implantation, as larger amplitude drops were associated with worse hearing outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Toward a Better Understanding of Electrocochleography: Analysis of Real-Time Recordings. Weder, S., Bester, C., Collins, A., et al.[2021]

Citations

1.

pubmed.ncbi.nlm.nih.gov

pubmed.ncbi.nlm.nih.gov/32925842/

3 and 12 Month Outcomes

Conclusion: Patients exhibiting ECochG drops during implantation had significantly poorer hearing preservation 12 months later. These observational outcomes ...

2.

journals.lww.com

journals.lww.com/otology-neurotology/fulltext/2020/10000/intraoperative_observational_real_time.14.aspx

Otology & Neurotology

These results confirm that real-time intraoperative ECochG monitoring informs the preservation of hearing for extended periods of time after implantation.

3.

journals.plos.org

journals.plos.org/plosone/article?id=10.1371/journal.pone.0323493

A systematic review of intraoperative electrocochleography ...

The key outcomes assessed were the correlation between intraoperative ECochG patterns and postoperative residual hearing levels, as well as the influence of ...

4.

nature.com

nature.com/articles/s41598-021-98658-6

Using electrocochleography to detect sensory and neural ...

Sensory hearing loss will cause a reduction in both the CM and neural component in the eCochG, but this reduction is relatively larger for CM.

5.

sciencedirect.com

sciencedirect.com/science/article/pii/S2095881120300536

Review Article Electrocochleography in cochlear implantation

A recent study agreed that those experiencing decreases in ECochG responses intraoperatively showed significantly greater likelihood of hearing loss, but ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC12074592/

Bridging the gap: A systematic review of intraoperative ...

Overall, this study shows how 3-month hearing outcomes can be predicted from the correlation of four-point impedances and ECochG recordings made ...

7.

ncbi.nlm.nih.gov

ncbi.nlm.nih.gov/books/NBK599517/

Electrocochleography - StatPearls - NCBI - NIH

Electrocochleography (ECochG) is a testing procedure that enables the clinician to assess cochlear electrical potentials.

8.

clinicaltrials.gov

clinicaltrials.gov/study/NCT06268340

Hearing and Structure Preservation Via ECochG

One current hurdle to optimising hearing outcomes following cochlear implantation is the unavoidable trauma caused to the inner ear during implant surgery.

9.

oto.wustl.edu

oto.wustl.edu/intraoperative-measure-offers-hope-for-cochlear-implant-optimization/

Intraoperative measure offers hope for cochlear implant ...

ENT surgeons at WashU Medicine are using an intraoperative measure called electrocochleography to optimize cochlear implants.